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-rw-r--r--kernel/irq/manage.c21
1 files changed, 21 insertions, 0 deletions
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 89a3ea82569b..9a35ace38bb1 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -1031,6 +1031,27 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
* all existing action->thread_mask bits.
*/
new->thread_mask = 1 << ffz(thread_mask);
+
+ } else if (new->handler == irq_default_primary_handler) {
+ /*
+ * The interrupt was requested with handler = NULL, so
+ * we use the default primary handler for it. But it
+ * does not have the oneshot flag set. In combination
+ * with level interrupts this is deadly, because the
+ * default primary handler just wakes the thread, then
+ * the irq lines is reenabled, but the device still
+ * has the level irq asserted. Rinse and repeat....
+ *
+ * While this works for edge type interrupts, we play
+ * it safe and reject unconditionally because we can't
+ * say for sure which type this interrupt really
+ * has. The type flags are unreliable as the
+ * underlying chip implementation can override them.
+ */
+ pr_err("genirq: Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
+ irq);
+ ret = -EINVAL;
+ goto out_mask;
}
if (!shared) {
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